Most knowledge about nucleic acid cleavage has resulted from the study of enzymatic or non-enzymatic cleavage of nucleic acids in vitro. It may be expected that such findings will not always be consistent with how similar systems behave in vivo. Moreover, the contribution nucleases make to health, and their role in cell death associated with almost any disease, have garnered more attention in recent years. For example, human recombinant DNase I is used to treat patients with cystic fibrosis whose airways become blocked by thick mucus containing high concentrations of bacterial DNA, and is being evaluated for the treatment for humans with systemic lupus erythematosus. Hence, there is a need in the art for nucleic acid probes that can be used to detect and quantify nucleic acid cleavage in vitro, in situ, ex vivo, and in vivo.